Device for hypodermic injections



Dec. 23, 1952 P. KOLLSMAN 2,622,595

DEVICE FOR HYPODERMIC INJECTIONS Filed Dec. 20, 1947 I. H grill/111m llgym/1171101404;

Fig. 5

INVENTOR. P g UL KOLLSMHN 5),, ATTORNEY Patented Dec. 23, 1952 UNITEDSTATES PATENT OFFICE DEVICE FOR HYPODERMIC INJECTION 8 Paul Kollsman,New York, N. Y.

Application December 20, 1947, Serial No. 792,992

1 Claim. 1

This invention relates to improvements in syringes for hypodermic orintramuscular injection of medicinal compositions. The inventionprovides a double purpose syringe which is inexpensive to manufactureand which serves as ampoule for storing a predetermined volume of amedicinal composition. The composition is discharged from theampoule-syringe directly into body tissue without previous transfer to aseparate syringe or other injection device.

The invention also provides a syringe which is extremely simple tooperate, one single manipulation of the syringe being sufiicient toapply it to the patient, insert the needle and eject the medicinalcomposition therefrom. The simple and inexpensive construction proposedby the invention makes it advantageous to discard rather than refill thesyringe after discharge of the medicinal composition therefrom.

The invention offers in this connection various structural improvementswhich make syringes non-refillable whereby unauthorized refilling undernon-sterile conditions is guarded against.

These and numerous other features, advantages and objects of theinvention will appear more fully from the detailed description whichfollows accompanied by drawings showing, for the purpose ofillustration, preferred embodiments of the invention. The invention alsoconsists in certain new and original features of construction andcombination of elements hereinafter set forth and claimed, Although thefea tures characteristic of this invention which are believed to benovel will be particularly pointed out in the claim appended hereto, theinvention itself, its objects and advantages, and the manner in which itmay be carried out may be better understood by referring to thefollowing description taken in connection with the accompanying drawingsforming a part of this application in which:

Figure 1 is a cross-sectional view of a syringe embodying the invention,a section being taken on line l--I of Figure 2;

Figure 2 is a plan view of the syringe shown in section in Figure 1;

Figure 3 is a side view, partly in section, of a Figure 5 is aperspective view of a stop member attachable to the plunger shown inFigure 1.

In the following description and in the claims, various details will beidentified by specific names for convenience. The names, however, areintended to be generic in their application. Like reference charactersrefer to like parts in the several figures of the drawings.

In the drawings accompanying, and forming part of this specification,certain specific disclosure of the invention is made for the purpose ofexplanation of broader aspects of the invention, but it is understoodthat the details may be modified in various respects without departurefrom the principles of the invention and that the invention may beapplied to other structures than the ones shown.

The subject matter of this application is related to the subject matterof co-pending applications directed to devices of the general typedisclosed herein.

Application Serial No. 792,991, filed December 20, 1947, now Patent No.2,578,812, dated December 18, 1951, discloses and claims a syringe inwhich the depth of insertion is automatically controlled and limited,and in which stop means are provided permitting measured partialdischarge.

Application Serial No. 792,993, filed December 20, 1947, now Patent No.2,578,813, dated December 18, 1951, discloses and claims a tubularneedle seal for a syringe which prevents contamination of the needle andis blow-off proof in that it will not blow 011 if thesyringe fluid issubjected to a sudden rise in pressure, for example by dropping thesyringe.

Application Serial No. 792,994, filed December 20, 1947, now Patent No.2,578,814, dated December 18, 1951, discloses and claims a syringehaving a narrow visible and optically enlarged passage leading to theinner end of the needle to facilitate observation, and expulsion of, gasbubbles in the syringe chamber.

Application Serial No. 792,995, filed December 20, 1947, discloses andclaims an improved form of non-creeping plunger seal. The syringe shownin Figures 1 and 2 comprises a barrel l l in which. a plunger 12 istelescopically movable. The plunger I2 is tightly sealed with respect tothe interior surface l3 of the barrel by a gasket [4 which rests in agroove l5 of the plunger and frictionally engages the interior surface13 of the barrel H.

In order to make the syringe unfit for re-use after discharge, thebarrel H and plunger l2 are preferably made from a thermo-responsivepreferably clear synthetic plastic which at ordinary room temperaturesis hard and shape retaining and which, upon heating to sterilizingtemperatures, of the order of the boiling point of water, becomesplastic and loses its shape or changes its appearance, for example byturning opaque. This property of the plastic material makes the barreland plunger unfit for use after an attempt to sterilize them by heating.Sterilization of the needle alone is discouraged by making it.non-.removable.

However, the barrel and plunger may initially. be sterilized by themanufacturer or thepharmaceutical laboratory distributing thefilledsyringes by exposing the parts to an atmosphere of sterilizinggas.

In the illustrated form of syringe, the rear-- surface I6 of the plungerforms a movable wall of a chamber I! adapted. to contain a charge ofmedicinal fluid confined between the barrel H and the plunger I2.

A hollow injection needle 18, preferably of'substantially constant outerdiameter, is non-removably mounted in, the plunger 12 and communicateswith the chamber H through a hollow passage l'9 extending through theplunger.- The needle 18 projects from the front end surface 20 of theplunger a distance d equalto the depthto which the needle is to be,inserted intothc body tissue.

The front end" surface 20 is substantially flat and comprises an, arealarge enough t,0 provide suflicient resistance for ejection ofthemedicinal composition from the syringe without causing discomfort tothe patient by reason of excessive local pressure.

The plunger may be provided with adjustable stop means to permitstep-by-step discharge of the contents of the syringe. In the form; ofsyringe shown in Figures 1 and 2, the piston is provided with aplurality of circumferential grooves '21 into which a movable stop 22;fits. The stop 22 is preferably made of plastic sheet material and has ajaw-shaped portion 23 adapted frictionally to engage any of the grooves2| in the piston. Attachment of the-stop 22 limits the freedom oftelescoping movement of the piston l2, the end of the preset strokebeing reached when the stop abutsthe end surface 24; of the barrel.

The plunger I2 is suitably calibrated in terms of'volumetric units; Thismaybe done byapplying scale numerals 25 to the ridges above therespective grooves-for the stop '22. For example, the nuzneral 1.5indicates that if the stop 22 is placed in the groove 2| below thenumeral 1.5, the volume; discharged atthe time the stopabuts the barrelII- is 1.5 volumetric units. Thisarrangement permits any-"desiredfractional volume to bedlschargedfrom the syringe.

Refilling of the syringe is mechanically discouraged by making theplunger l2 ofa length Z1 equal to, or slightly-less than, thelength Z2of the barrel, measured on the, inside so that in fully telescopedposition the plunger is completely within the barrel l l and cannot beremoved therefromby hand for thepurpose of refilling. The friction whichthe gasketl 4 provides against the interior surface [3 is sufficient topreventwithsurface 20;

4 drawal of the plunger from the barrel by a needle I8.

The syringe shown in Figures 1 and 2 is primarily designed for fillingwith a medicinal fluid composition at the plant or laboratory of theproducer, the volume of the fluid being sufficient for a singleinjection or a series of injections by operating the syringe in repeaterfashion with the aid of the adjustable stop 22 as hereinbeforeexplained. After initial filling, the syringe is sealed by placing overthe end of the needle l8 a sealing plug 28 preferably of rubber or anyother suitable material. This plug pressure tightly seals the end of theneedle to prevent discharge of the fluid therefrom in the eventthesyringe is accidentally subjected to telescoping force and to maintainthe front end of the syringe sterile.

In sealed condition, the syringe serves as an ampoule and is ready forimmediate use by removal of the sealing plug 28 and adjustment of thering 22, if the syringe is equipped with such a ring.

Small air bubbles accidentally trapped in the chamber If during thefilling of the syringe may easily be removed by placing the filledsyringe in an upright position thus causing the bubbles to rise and,collect near the, passage, l9, Collection of. the,- hubblesisfacilitated by the conical shape of the rear surface Hi ofjthe plun er[2' as shown in the, drawings. Slight telescoping movement of theplungerl2 withrespect to the barrel I I forces the bubbles, out through thepassage 19 and the needle-1B.-

syringe showninFigurcs 1 and 215 used as follows. After remoyal ofthesealing plug 28 from the, injection needle E8, the, device is ready forimmediate use. It is applied to the body of apatient by grasping it atthe barrel l I which provides afinger grip surface or portion 29. Thepoint. of the needle I8 is placed'on the patients shin andpressure isthen exerted in the direction of the needle l 8' to insert the needleinto the body tissue. This force does not cause any discharge from thesyringe because. in the initial. state in which the plunger gasket l 41is stationary with respect to the barrel surface E3 the frictiontherebetween is relatively great and is equivalent to a multiple of; theforce required for inserting the needle to its full length.

The needle IBpenetrates the body tissue until the front end surface 20,of the plunger comes to rest onthe patients skin, whereafter the forceexerted at the barrel is opposed by an equal pressure exerted by theskin againstv the front This is sufiicient to overcome the frictionof'the gasket [4 andthe barrel H then moves telescopically over theplunger causing the fluid to be discharged through the passage l9 andthe needle i8 intothe patients body tissue. The, dischargecontinuesuntil either the plunger reaches its end position in the barrel,or until the adjustable rin 22 engages the frontsurface 2 ofthe barrelin the case of partial discharge.

After completedischarge of the fluid from the syringethe syringe isdiscarded, The low production price and the difficulty of removal of theplunger from the barrel due to its peculiar construction discouragesattempts of re-usingit Figure 3 illustrates a modifiedform of syringecomprising a barrel 3!! Within which a plunger 31 is telescopicallymovable. The plunger may be made from tubular round stock. It isslotted'at 32 and an elastic plug 35 inserted between the slottedplunger portions tends to force the slotted portions apart to providesufficient frictional engagement of the plunger with the interiorsurface 33 of the barrel. The plunger may have an enlarged fingeroperable grip portion 34 and may be provided with a scale 35 readableagainst the back surface 36 of the barrel.

A movable seal or membrane 31, preferably separate from the plunger 3|is telescopically movable in the barrel and forms a seal of the fluidchamber 38 against the piston 3 I An injection needle 39 is mounted inthe front end Q0 of the barrel and extends in the illustrated embodimentwith its pointed rear end 4| into the chamber 38 to pierce the centerportion 42 of the seal 31 when the seal arrives in its end position.Since the seal 31 is not attached to the plunger, it cannot be removedfrom the barrel by withdrawal of the plunger. Refillin of the syringe isthus discouraged by the difficulty of removing the seal from the barreland is further rendered impossible by destruction of the seal once thesyringe is fully discharged.

Air or gas bubbles accidentally trapped in the chamber 33 may be removedby placing the syringe in an upright position causing the bubbles tocollect at the conical end surface 46 of the chamber 38. Slight movementof the plunger 3| then expels the bubbles through the needle 39.Experience has shown that movable seals or pistons 31 of elasticmaterial have a tendency slightly to creep back at the rim portion afterthe pressure by the plunger on the seal is released. Such creeping ofthe seal 3? may cause a small air bubble to be drawn into the chamberthrough the needle. According to the invention,

creeping of the seal 31 is prevented by frictional fit of the plunger 3!within the barrel 3%. The elastic plug 3| which forces the slotted endsof the plunger 3| apart and against the wall 33 of the barrel providessufficient friction to check any creeping of the seal, the frictionalforce being greater than the elastic force of deformation of the seal 31at the rim portion tending to move the seal back slightly.

The thin center portion 42 of the seal 31 also aids in preventing airfrom being drawn into the chamber 38. During discharge of fiuid from thechamber 38, the center portion 42 is bulged rearwardly to some extenttowards the plunger by reason of the fiuid pressure upon it. When thepiston 3| comes to rest and the pressure inside the chamber 38 drops,the center portion 42 of the seal returns to its normal position and indoing so tends to force out an additional small volume of fluidsufiicient to compensate for any creeping of the seal near its rimportion which would tend to draw fluid into the chamber 38.

The syringe shown in Figure 3 is likewise designed for one-time use tobe filled at the laboratory or factory. It may be sealed by anappropriate sealing plug 28 for shipment and storage in sterilecondition until the time of its use.

When the syringe of Figure 3 is to be used, the sealing plug 28 isremoved from its needle 39 and the front end 40. The syringe is graspedby the finger operable portion 34 of the plunger M and is placed on thepatients skin. Pressure exerted on the plunger forces the needle 39 intothe body tissue until the front end 48 of the barrel comes to rest onthe patients skin. No fluid is expelled from the syringe during theinsertion of the needle since the resistance of the needle to insertionis not sufficient to overcome the friction of the movable seal 31. Afterthe needle 39 is completely inserted into the tissue 6 of the patient,further movement of the piston 3| is opposed by reaction of the skinagainst the front end M] of the barrel. This resistance is sufficient toovercome the frictional resistance of the movable seal 31 and liquid isnow forced out through the needle 39. At the end of the stroke, thepointed rear-end 4! of the needle pierces the thin center portion 42 ofthe seal and automatically renders the syringe unfit for refillingwithout removal and replacement of parts.

The invention thus provides a syringe which, because of its simplicity,is inexpensive to manufacture by modern mass production methods. Thecostof the syringe is so small as to make one-time use and discarding afteruse more profitable than re-use of the syringe.

Safe re-use of a syringe involves inspection, sterilization andre-filling under sterile conditions. Conditions of sterility aredifficult to maintain except at establishments specifically equipped forit, for example, laboratories, hospitals and physicians offices.

Syringes, according to the present invention, lend themselves admirablyto use by the patient himself, who, but for rare exceptions, has nofacilities for the cleaning, sterilization and refilling of syringes,thus opening the doors to dangers of infection. The present inventionmeets a specific need in providing a syringe which is furnished by apharmaceutical laboratory ready-filled with a specific volume ofmedicina1 composition ready for immediate use by the patient. Thesyringe reaches the patient in sterile condition and requires no fillingor transfer of medicinal fluid from one receptacle into another. Thenovel syringe thus permits maintenance of a degree of sterility by theaverage patient which he was not heretofore able to maintain. Thesyringes embodying the principles of the invention are practicallyfool-proof in use. They are also particularly safe to use by reason ofthe limitation of the depth to which the needle may be inserted into thebody tissue whereby the danger of improper injection or injury due tocontact of the injection needle with bone structure of the patient iseliminated. Thus, a degree of safety is provided in theselfadministration of injections which prior to the invention was notregularly attained.

The invention obviously is not restricted to the particular embodimentsherein shown and described. Numerous modifications, additions,omissions, substitutions and other changes may be made without departingfrom the spirit and the essence of the invention as defined in theappended claim. All uch changes will be apparent to persons skilled inthe art familiar with the disclosure of the invention and do not involvea departure from the spirit and the teachings of the invention.

What is claimed is:

An injection syringe comprising, in combination, a barrel; means forminga movable wall in said barrel, said means including a plungertelescopically fitting into said barrel and a plug of resilient materialfor sealing said barrel towards said plunger, whereby a variable volumechamber is formed in said barrel adapted to contain a charge ofmedicinal fluid; a hollow injection needle mounted on said barrelcommunicating with said chamber, said needle projecting from the frontend surface of said barrel; said plunger having a plug engaging endportion slotted lengthwise of the plunger; and a resilient Number memberfor forcing said slotted end portion apart 4, into frictional contactwith the barrel wall. 4 PAUL KOLLSMAN. 11 5, 2,388,323 REFERENCES CITED2,408,323 The following references are of: record in the 21478344 fileof this patent:

UNITED STATES PATENTS 10. Number Number Name Date 2 1 4 Re. 16,836 Cook:Dec. 27,. 1927 51 54 446,125 Schirmer Feb. 10, 1891 573,611 509,676Billing et a1 Nov. 28, 1893 632,383 1,272,742 Weguelin et a1 Ju1y'16,1918 15 Name Date Rehm Mar. 12, 1929 Morton June 24, 1930 Hall Mar. 18,1932 Henderson Nov. 6, 1945 Lockhart Sept. 24, 1946 Smith Aug. 9, 1949FOREIGN PATENTS Country Date Great Britain June 15, 1901 SwitzerlandMar. 1, 1910 Great Britain Nov. 18, 1945 Germany July 15, 1936

